David Harper
Research Interests
An extraterrestrial trigger for the mid-Ordovician ice age : Dust from the breakup of the L-chondrite parent body
Author
Summary, in English
The breakup of the L-chondrite parent body in the asteroid belt 466 million years (Ma) ago still delivers almost a third of all meteorites falling on Earth. Our new extraterrestrial chromite and 3He data for Ordovician sediments show that the breakup took place just at the onset of a major, eustatic sea level fall previously attributed to an Ordovician ice age. Shortly after the breakup, the flux to Earth of the most fine-grained, extraterrestrial material increased by three to four orders of magnitude. In the present stratosphere, extraterrestrial dust represents 1% of all the dust and has no climatic significance. Extraordinary amounts of dust in the entire inner solar system during >2 Ma following the L-chondrite breakup cooled Earth and triggered Ordovician icehouse conditions, sea level fall, and major faunal turnovers related to the Great Ordovician Biodiversification Event.
Department/s
- Nuclear physics
- MERGE: ModElling the Regional and Global Earth system
Publishing year
2019-09-18
Language
English
Publication/Series
Science Advances
Volume
5
Issue
9
Document type
Journal article
Publisher
American Association for the Advancement of Science (AAAS)
Topic
- Geology
Status
Published
ISBN/ISSN/Other
- ISSN: 2375-2548